SIR – In your special report on the Arctic (“The melting north”, June 16th) you said polar bears are “struggling” and it is “nonsense” that they are thriving. Anything other than a cursory reading of the data shows no such thing.

According to the International Union for Conservation of Nature estimates, polar bear numbers are at least twice as high as in the 1960s. Of the eight populations said to be decreasing, the official data table and map produced by the Polar Bear Specialist Group shows that two are only “thought” or “believed” to be declining entirely due to hunting; four are in decline only according to computer models, despite some claims by “traditional ecological knowledge” (ie, locals) that they are thriving; one has more than doubled but is now said to be “currently declining” because of crowding; and one showed a real decline that has recently been reversed. Meanwhile, the four populations you described as unknown include the huge Barents Sea population, which has seen dramatic increase in sightings, damage to huts and devastation of barnacle goose colonies on the west coast of Svalbard, all prima facie evidence of “thriving”. There is a strong smell of “policy-based evidence making” here.

Since the 1970s the population of white whales around Svalbard has increased, as have walrus and barnacle geese numbers. Protection from hunting has had, and is likely to have, a much bigger impact on Arctic wildlife than climate trends.

Matt RidleyNewcastle-upon-Tyne

Andrew MontfordMilnathort, Kinross-shire

Benny PeiserLondon

Corruption costs

SIR – Your article (“You get who you pay for”, June 2nd) left unchallenged the argument that bribery is a “solid investment”, giving the impression that corruption can be good for the business that secures a deal through graft.

Narrow findings that show bribery can boost a company's share price fail to take into account the many other substantial costs of bribery and corruption. Not only do they impact company morale and reputation, but they skew the level playing field that companies need for markets to operate smoothly. There are also costs to society in terms of human rights, the environment and economic sustainability. Research has shown systemic bribery and corruption can add as much as 10% to the total cost of doing business globally and 25% to the cost of procurement contracts in developing countries.

Today more investors and consumers are seeking out companies that take comprehensive and effective anti-corruption measures for ethical reasons and risk management, a win-win for stockholders and stakeholders alike. Surely this bigger picture is a better indicator for long-term business benefit than a stockmarket blip in the wake of a bid won by bribes.

* SIR – Your leader didn't mention the “Gaza liberation” rhetoric on the streets Egypt (“Egypt in peril”, June 23rd), nor the Gazan Muslim Brotherhood's close ties with Hamas (who publicly pledged allegiance, vowing their lives as support), nor the celebrations in Gaza when Muhammad Morsi was proclaimed president of Egypt only six hours after vote-counting started. You didn't mention Ismail Haniyeh's speech refuting peace treaties with Israel a few months ago at Al-Azhar university, a symbol of moderate Islam throughout history. And I'm sure you are aware of the state of fear Egypt's Christians are living in, and how Christian and female MPs have been alienated by Islamists in the parliament since their first session.

The army shouldn't give up its powers yet. Egypt, if it is lucky, could well become another Turkey, and just sacrifice freedom of press and close a few churches, but it could also become another Afghanistan, Iran, Sudan or Gaza. The coming Islamist powers have no precedence and are giving no guarantees about which direction they will take the country in. The army's hand should be lifted gradually so it is still able to intervene if characteristics of civil states are undermined or minorities are threatened.

Rahim ElkishkyCairo

Double standards

SIR – Lexington (June 23rd) said that Florida's senator Marco Rubio has not yet found a way to be “a bridge between the Republican Party and alienated minorities”. That's hardly surprising considering his legislative record. Florida's Republicans have been adamantly opposed to governmental support for medical insurance for those who can ill afford it, and were at the forefront of the attack by some states against Obamacare. But, when homeowners in Florida experienced difficulty in getting storm insurance for their property, these same Republican politicians had no qualms about establishing a state-supported entity—citizen's insurance—to provide cover. Their programme even has gone so far as to be specifically permitted to be actuarially unsound.

Mr Rubio is one of those pseudo-conservatives who are more appropriately described as “selective socialists”. John Kenneth Galbraith described the situation when he wrote that the only respectable type of socialism in America was socialism for the rich.

Palmer HansonBrevard, North Carolina

The market view

SIR – You claimed that the “markets see France as more like Spain or Greece than Germany or Austria” (“Powerful as well as dangerous”, June 23rd). At the time of writing, the yield on benchmark 10-year French bonds stood at 2.6%, representing a spread of just over 100 basis points over its German equivalent. Spanish and Italian spreads, on the other hand, stood at 480 and 420 basis points respectively. Although France's economic fundamentals are, in some areas, worse than those of Italy and Spain, the bond markets treat France as a weaker version of Germany as opposed to a stronger one of Spain. Whether this distinction persists is another matter.

Nicholas SpiroLondon

Home sweet home

* SIR – Thank you for highlighting the failings in the British rental market (“Housing the 'rentysomethings'”, June 23rd). I agree that unprofessional landlords pose a problem. Yet by far the biggest culprits are estate and management agencies. Their staff habitually misinform prospective tenants about properties, talk the former into short-term leases, impose crippling contracts, take ages to return the signed documents, respond to complaints only slowly and deduct money from deposits based on spurious charges—all in return for hefty commissions. The answer is better tenant protection, including a minimum three-month notice, which tends to be standard in the rest of Europe. Or landlords and tenants should bypass agencies entirely as they evidently offer little value for money. Both steps would encourage long-term relationships, which tenancies can and should be.

Manuel BollagLondon

Early slavery

SIR – Your review (“Gold in white and black”, June 16th) was misleading about the history of slavery in the New World. To say Barbados was “the first colony to import slave labour” ignored the 100-year head start of this enterprise in Portuguese Brazil. Moreover, calling England “the world's most active slaving nation” failed, again, to credit Portugal as the dominant slaving colonial power. The reference to the 12m to 15m slaves in “these colonies” included not only the English ones, but also the Portuguese, French, Spanish and Dutch.

Maybe you have fallen into the American frame of mind; they think that their own nation's sin of slavery is the only one that counts.

Robert RaceGeneva

Honey for money

SIR – I see that the fable of the bees lives on (“The real wealth of nations”, June 30th). You stated “[Bees] also pollinate nearby apple trees, a useful service that is not purchased or priced.” As Steven Cheung said in his 1973 paper, “The Fable of the Bees: An Economic Investigation”, pollination by honeybees is, and has been for many years, a service that is purchased and priced in a vibrant market. Each year millions of colonies of bees are shipped around the country to pollinate orchards for monetary compensation. Beekeeping is an example of a mispriced asset that has long been discredited.

Jacob BurgdorfClemson, South Carolina

Exit signs

SIR – Simon Buxton's suggestion of “Grexodus” may have a certain charm compared with “Grexit” (Letters, June 23rd), but its combination of Greek and Latin morphemes is more hybrid than Aegean coinage. “Hellenexodos”, rather, is a pure Greek compound.

In any event, the biblical resonances of exodus mean that “Grexit” is probably here to stay: Europe is certainly no promised land at the moment, but Antonis Samaras cuts a poor Moses and Angela Merkel a worse Pharaoh.

Michael SampsonWinnipeg

SIR – Bagehot said, “A Brixit looms” (June 23rd). Yes, indeed. But at the same time “a BRICs-in” beckons, does it not?